When I run it on my Windows desktop on a local WAMP server I get the following error and looking at the smf files none of them has been changed:

--- Quote ---This script resets all files to the default installation from the file "test_reset.zip" (which is a pared down version of the "Large Upgrade Package" from SMF.)This script will also remove all installed themes other than the default, reset all packages to "not installed" and reset all member options to the default settings for the default theme. Remember: This will not remove any mod DATA from the database, nor will it delete the mod-specific FILES